1. Field of the Invention
The present invention relates to a brake lining bonding apparatus which is used for bonding a lining onto a brake-shoe of a drum brake and relates to a registry mechanism for properly positioning brake-shoes and linings in the apparatus.
2. Description of the Prior Art
A conventional bonding apparatus of this type has been disclosed, as shown in FIG. 14, in Japanese Patent Laid-Open Application No. 134832/78 in which a pair of brake shoes 62 T-shaped in cross section are positioned at the inner side a loop-shaped pressure imposing band 61. Linings 63 applied with a bonding agent of a heat-hardening type on their surfaces are disposed between the brake-shoes 62 and the pressure imposing band 61. A pair of pronged members 65 on the left hand side of an expanding member 64 and another pair of pronged members 65 on the right hand side of the expanding member 64 are allowed to fit to a respective rib 66 of the brake shoes 62. The expanding member 64 is caused to expand in opposite directions by a plurality of springs 67 interposed between the left and right parts of the expanding member 64.
The brake shoes 62 are urged outwardly toward the linings 63, and the brake shoes 62 are bonded to the respective linings through heat treatment. The pressure imposing band 61 is formed of spring steel, both ends of which are welded to each other. This pressure imposing band 61 is substantially circular when it is in relaxed condition.
In the above conventional apparatus, the pressure imposing band 61 is first removed from the outer circumference of the brake shoes 62, then the brake shoes 62 are removed from the pronged portions 65, thus requiring complicated steps in order to operate the apparatus. Since the apparatus is so arranged that the pronged portions 65 of the expanding member 64 fit to the ribs 66 of the brake shoes 62, it is required, in setting up prior to bonding, to fit the ribs 66 to the pronged portions 65 and then to fit the pressure imposing band 61 to the linings 63 applied to the outer periphery of the brake shoes 62.
Furthermore, a disassembling operation after the bonding operation requires the complicated steps of removing the pressure imposing band 61 from the brake shoes 62 while compressing the springs 67, and then removing the respective brake shoes 62 from the pronged portions 65 of the ribs 66 by shaking the brake shoes left and right. Thus, the conventional apparatus requires many complicated steps and, therefore, bonding work may be very difficult to automate, leading to high manufacturing costs.
The above-mentioned conventional apparatus is arranged so that the end portions 62a, 62b of the inner circumference of the brake shoes 62 abut the end portions so the brake shoes 62 have some play in circumferential direction with respect to the expanding member 64 and, accordingly, simple loading of the brake shoes does not assure proper positioning of the brake shoes. Thus, there has been a drawback that the brake shoes 62 have to have their positions individually aligned by visual observation every time they are loaded.
Further, in the conventional apparatus, the pronged portions 65 of the expanding member 64 fit to the ribs 66 of the brake shoes 62. Simply compressing the springs 67 does not allow loading of the brake shoes 62 nor removing of the brake shoes 62 after bonding. In addition, the pressure imposing band 61 is also required to be removed every time, thereby increasing the operating steps to follow.
Furthermore, the aforementioned conventional apparatus has no mechanism for holding the longitudinal ends of the lining 63, thus simply installing the lining 63 does not assure its longitudinal, proper positioning. Thus, another drawback is that the positions of linings 63 have to be aligned by visual observation every time they are loaded.